Sealing and safety device for filling a hollow body with a liquid

ABSTRACT

Sealing and safety device made from flexible elastomer material, for filling a hollow body with a liquid using a delivery nozzle, comprising an annular seal for surrounding the nozzle and preventing the exit of gases from the hollow body and also a valve capable of opening, in the event of excess overpressure in the hollow body, only towards the external atmosphere so as to create a passage allowing the escape of liquid and/or of gas.

The present invention relates to a sealing and safety device for fillinga hollow body with a liquid.

A number of safety systems for fuel tanks have been described,addressing, generally speaking, the solution of problems linked todegassing of the tank during filling thereof and its venting to the airduring a normal period of rest and of functioning of the engine that isconsuming said fuel. In addition to these problems, there is anincreasingly imperious need, regarding respect for the environment, torecover the vapours that are released during the above-mentionedoperations, while minimizing leakages to the atmosphere.

Various systems that achieve reasonably complete sealing between adelivery nozzle and a filling orifice of a tank are known. Patent U.S.Pat. No. 3,334,779, for example, discloses a diaphragm made fromflexible material that is slit into three segments. Pushing the nozzlein opens the diaphragm and separates the segments on the inner wall ofthe filler neck, where they act as a seal for the delivery nozzle.

The known systems, however, present a number of disadvantages:

-   -   creation of an overpressure in the tank, giving rise to returns        of liquid in the filler neck;    -   absence of recovery of liquid vapours via the nozzle;    -   no protection in the event of surges in the tank.

An object of the invention is to remedy the drawbacks of known systemsand to provide a system that manages rapid increases in pressure in thetank while maintaining the system's small overall size and a low cost ofthe same order of magnitude or less than that of existing conventionalsystems.

To this end, the invention relates to a sealing and safety device madefrom flexible elastomer material, for filling a hollow body with aliquid using a delivery nozzle, comprising at least one annular seal forsurrounding the nozzle and preventing the exit of gases from the hollowbody, according to which it also comprises at least one valve capable ofopening, in the event of excess overpressure in the hollow body, onlytowards the external atmosphere so as to create a passage allowing theescape of liquid and/or of gas from the inside of the hollow bodytowards said external atmosphere.

The invention relates to a sealing and safety device. “Sealing device”is understood to denote any device capable of isolating the internalatmosphere of a hollow body from the ambient atmosphere. “Isolate” isunderstood to denote, in this case, allowing only a slight leakageduring use of the device. The permitted leakage level is regulatedduring fitting of the sealing and safety device so that, at a testpressure of 40 mbar relative to atmospheric pressure, the leakage doesnot exceed 20 l/hour and, preferably, 12 l/hour.

The device according to the invention is also a safety device, i.e. asystem for storing and handling a liquid in a tank in a manner that issafe for the user and for the environment. Such a system shields theuser from any hazardous situation, particularly any risks of explosion,implosion, combustion or pollution, while maintaining the externalenvironment free of any leakage of liquid or emanation of undesirablegases.

According to the invention, the sealing and safety device is produced ina flexible elastomer material, i.e. a material that is able to deformelastically through the influence of a mechanical stress.

All categories of elastomer materials are suitable, such as, forexample, natural elastomers, such as rubber, and the various syntheticelastomers. Of the latter, artificial rubbers, and synthetic copolymersand polymers having elastomeric properties are especially suitable. Ablend of a number of polymers and/or copolymers may also be suitable inso far as at least one of the components of the blend has elastomericproperties. Examples of such materials are butadiene-styrene resins,optionally combined with a third component, thermoplastic polymers suchas polyolefin elastomers or olefin elastomer copolymers.

The device according to the invention is for filling a hollow body.“Hollow body” is understood to mean any structure whose surface has atleast one void or concave part. Preferably, “hollow body” denotes inthis case a closed structure for containing a liquid and/or a gas. Vatsand tanks are particularly preferred. The hollow bodies according to theinvention are particularly well suited to their use as a fuel tank,particularly those present on—or designed for equipping—motor vehicles.

The liquid filling the hollow body may any type of inorganic and/ororganic liquid. In particular, it may contain at least one dissolvedsubstance.

The device according to the invention is well suited to the filling oftanks with liquids whose volatility at ambient temperature is greaterthan the volatility of water and of aqueous solutions. It isparticularly well suited to filling fuel tanks with a liquid fuel suchas a gasoline or diesel.

According to the invention, the hollow body is filled using aliquid-delivery nozzle. Such a nozzle controls the arrival and thedelivery of liquid entering the hollow body. It is generally alsoprovided with a system for automatic triggering and shutoff of thedelivery of liquid when the hollow body is almost full.

According to the invention, the device comprises at least one annularseal for surrounding the nozzle. This annular seal comprises at leastone lip made from elastomer material that folds back on the outersurface of the nozzle spout pipe. A device with two annular lips hasafforded good results.

The annular seal is designed to oppose the exit of gases from the hollowbody. It is understood that a minimum leakage defined above in terms ofsealing is permitted.

According to the invention, the sealing device also comprises at leastone valve capable of opening, in the event of excess overpressure in thehollow body, only towards the external atmosphere so as to create apassage allowing the escape of liquid and/or of gas from the inside ofthe hollow body towards said external atmosphere.

“Excess overpressure” is understood to mean an accidental overpressurethat arises rapidly, such as is produced in the event of failure of theautomatic triggering system of the nozzle during filling. Such an excessoverpressure may also arise in extreme abnormal situations such asrapid, high temperature rises in the event of fire or explosion, forexample. The function of this valve is to preserve the integrity of thehollow body and to prevent any bursting of or damage to the hollow bodyduring such accident situations.

When it opens, the valve creates a passage to the external atmosphere inthe immediate vicinity of the hollow body.

A particular embodiment of the valve according to the invention is thatof an annular lip made from elastomer material. In this embodiment, oneend of the lip may be integral with the sealing device and its other endmay bear with elastic force on a rigid element bordering the passage.“Rigid” is understood to mean the condition of a material that is notelastic.

In the open position, the lip preferably uncovers an orifice that allowsthe flow of the liquid and/or of the gas. This orifice may be pierced ina rigid part close to the passage. The orifice preferably allows a flowof liquid and/or gas in an initial direction perpendicular to the axisof the delivery nozzle.

Also, the rigid element preferably borders the orifice. Most preferably,this rigid element delimits the orifice, constituting its entirecircumference.

Another particular embodiment of the valve according to the invention isthat of a non-return flap valve. The flap valve may be independent ofthe annular seal. It is advantageously located close to the dispensingnozzle when the latter is engaged in the sealing and safety deviceaccording to the invention. All forms of non-return flap valves that arecompatible with the environment of the passage may be used.

One example of a non-return flap valve that is particularly suitable isthat of a membrane made from elastomer material in the form of aninverted umbrella.

An interesting variant embodiment of the device according to theinvention is that in which the device also comprises, on the hollow bodyside, an obturator made from elastomer material. The obturator isarranged downstream of the device, in the direction of insertion of thedelivery nozzle. It may have any shape that is compatible with thesealing and safety device. One example that has afforded good results isan obturator formed by a diaphragm made from elastomer material, such asthat formed by a disc of such material slit into at least four segments.

The device according to the invention is most particularly suited tohollow bodies that are tanks, for example fuel tanks, such as thosefound on motor vehicles.

When the hollow bodies are such fuel tanks, the device according to theinvention may advantageously be incorporated into a guide for thefuel-delivery nozzle. A guide of this type is generally inserted intothe top of a filler neck of a fuel tank. Its function is correctly toposition the nozzle in the top of the neck to allow problem-freefilling. Accessorily, it is generally provided also with a mechanicalpolarizing device with a view to preventing any filling with a grade offuel unsuitable for the vehicle in question. The guide may be made fromvarious materials, including metals and rigid plastics. Preferably, itis made from rigid plastic.

In the latter embodiment, in which the device according to the inventionis a part of a nozzle guide, the guide may itself be incorporated into awider fuel system that comprises a tank and a degassing andventing-to-the-air flap valve. The device is very suitable when theoverall fuel system also comprises a breather pipe for breathing of thevapours and for fixing the maximum liquid level in the tank. This pipeconnects the top part of the tank to the upper part of the filler neck,downstream of the sealing device, on the tank side. In this fuel system,the degassing and venting-to-the-air flap valve is often a float valve.The float line of the float is generally adjusted so that the flap valveis open only in two circumstances, namely when the tank is inclinedbeyond a predetermined limit, or even completely inverted, and during atransitory movement of the fuel whose extent exceeds a predeterminedvalue.

In this fuel system, the breather pipe for breathing of the vapours andfor fixing the maximum level that connects the top part of the tank tothe upper part of the filler neck, may be largely located outside thevolume of the tank and that of the filler neck. In this case, this pipepenetrates, at one of its ends, the upper wall of the tank and entersinto the top part of it. Also, at its other end, it penetrates thefiller neck, downstream of the sealing system.

In a variant embodiment, the breather pipe for beathing of the vapoursand for fixing the maximum level may be located entirely inside thevolume of the tank and that of the filler neck.

In the two above-described variant embodiments, the breather pipe forbreathing of the vapours and for fixing the maximum level preferably hasa diameter that is sufficiently large to allow total aspiration of thegases present in the tank via the nozzle.

Another variant embodiment that is compatible with the preceding ones,is that in which the breather pipe for breathing of the vapours and forfixing the maximum level opens out into the top part of the tank via afloat valve, different from the degassing and venting-to-the-air flapvalve, which closes the passage when the maximum level of liquid isreached in the tank.

The following FIGS. 1 to 4 aim to illustrate the invention withoutlimiting its scope in any way.

FIG. 1 illustrates a section through a sealing and safety device (6)made from elastomer material, incorporated into a high-densitypolyethylene (HDPE) guide (4). A delivery nozzle (5) is inserted intothe guide (4) and traverses the device (6). An annular seal comprisingtwo lips (12, 13) in elastomer material, which fold down on the outersurface of the pipe of the spout of the nozzle (5), guaranteesleaktightness. An obturator in the form of a diaphragm (14) extends thedevice (6) downstream and is illustrated in the position in which it hasbeen opened by means of the nozzle (5) having been pushed in.

A valve having the form of an annular lip (15) made from elastomermaterial is integral with the device (6) and extends it upstream. In thenormal position, the annular lip (15) rests closed on a rigid edge (71)formed of part of the guide (4). It covers an annular orifice (72)pierced in a rigid part of the guide (4). The form of the guide (4) inthe vicinity of the nozzle upstream of the sealing and safety device (6)provides a space (73) for the escape of gas and/or liquid.

In the event of an accidental surge on the inside (16) of the fillerneck, the lip (15) opens and uncovers the orifice (72), thus allowingthe creation of a passage for gases and/or liquid, in an initialdirection perpendicular to that of the axis of the nozzle (5), whichthen escape via the space (73) in order, finally, to reach the externalatmosphere (17) above the top of the guide (4).

FIG. 2 illustrates a section through another variant embodiment of asealing and safety device (6) according to the invention. In thisvariant embodiment, the orifice and the annular lip of FIG. 1 have beenreplaced by a valve in the form of a non-return flap valve (74) in theform of an upturned umbrella made from elastomer material. The end ofthe circumference of the umbrella (75) acts as a flexible circular lipthat opens through the influence of too-high a pressure on the inside(16) of the neck.

FIG. 3 shows a section through the top of a filler neck (2) comprisingthe sealing and safety device (6) according to the invention. It shows abreather pipe (8) for the vapours arranged inside the neck (2).

FIG. 4 illustrates a wider fuel system that comprises the top of thefiller neck (2), and also a fuel tank (1), a flap valve (7) with float(11) which is normally open, provided with a liquid-trapping volume (30)and a canister (18). A breather pipe (8) for breathing of the vapoursand for fixing the maximum level is separated into two parts ending oneither side of a non-return flap valve (31) designed to prevent exits ofliquid from the tank (1) in the neck (2). In the tank (1), the pipe (8)is extended by a siphon that ends in a section (9) entering the top ofthe tank and fixing the maximum permitted level of liquid.

FIG. 5 illustrates a variant embodiment of the top of the filler neck(2) in which the breather pipe (8) for breathing of the vapours and forfixing the maximum level is located outside the volume of this neck. Inthis variant embodiment, the pipe (8) remains outside the tank (notshown) over a major part of its length, penetrates the upper wall of thelatter and enters the top of the inner volume as far as the maximumpermitted level of liquid.

1. A sealing and safety device made from flexible elastomer material,for filling a hollow body with a liquid using a delivery nozzle,comprising at least one annular seal for surrounding the nozzle andpreventing the exit of gases from the hollow body and at least one valvecapable of opening, in the event of excess overpressure in the hollowbody, only towards external atmosphere so as to create a passageallowing an escape of at least one of liquid and gas from inside of thehollow body directly to the external atmosphere, the valve being anon-return flap valve, independent of the annular seal, that is locatedclose to the nozzle, wherein the non-return flap valve has the form ofan inverted umbrella and is made from elastomer material.
 2. The deviceaccording to claim 1, which also comprises, on the hollow body side, adiaphragm made from elastomer material.
 3. The device according to claim1, wherein the hollow body is a fuel tank.
 4. The device according toclaim 3, which is incorporated into a guide, made from rigid plastic,for a fuel-delivery nozzle inserted into the top of a filler neck of thefuel tank.
 5. A sealing and safety device made from flexible elastomermaterial, for filling a hollow body with a liquid using a deliverynozzle, comprising at least one annular seal for surrounding the nozzleand preventing the exit of gases from the hollow body and at least onevalve capable of opening, in the event of excess overpressure in thehollow body, only towards the external atmosphere so as to create apassage allowing an escape of at least one of liquid and gas from insideof the hollow body towards external atmosphere, the valve being anon-return flap valve, independent of the annular seal, that is locatedclose to the nozzle, wherein the non-return flap valve has the form ofan inverted umbrella and is made from elastomer material, wherein thehollow body is a fuel tank, wherein the device is incorporated into aguide, made from rigid plastic, for a fuel-delivery nozzle inserted intothe top of a filler neck of the fuel tank, and wherein the guide isitself incorporated into a wider fuel system that comprises a tank, aflap valve with float for degassing during filling and venting to theair during operation and a pipe for breathing of the vapors and forfixing the maximum liquid level in the tank, connecting the top part ofthis tank to the upper part of the filler neck, downstream of thesealing device, on the tank side, and in which the flap valve isnormally open during filling of the tank and during periods of operationand the float line of the float is adjusted so that the flap valve isclosed only in two circumstances, when the tank is inclined beyond apredetermined limit and during a transitory movement of the fuel whoseextent exceeds a predetermined value.
 6. The device according to claim5, wherein the breather pipe for the vapors that connects the top partof the tank to the upper part of the filler neck is located entirelyinside the volume of the tank and that of the filler neck.
 7. A sealingdevice for filling a body with a liquid using a nozzle, comprising: anannular seal configured to surround the nozzle to prevent a gas fromescaping from the body; and a valve configured to vent the liquid or thegas from the body directly to atmosphere when a pressure of the liquidor the gas in the body exceeds a predetermined pressure, the valvecomprising a non-return valve, and the valve being independent of theannular seal.
 8. The sealing device according to claim 7, wherein atleast one of the valve and the annular seal comprises an elastomermaterial.
 9. The sealing device according to claim 7, wherein each ofthe valve and the annular seal comprises an elastomer material.
 10. Thesealing device according to claim 7, wherein the annular seal comprisesat least one annular lip configured to limit the gas from escaping fromthe body between the nozzle and the annular seal.
 11. The sealing deviceaccording to claim 7, wherein the annular seal comprises at least twoannular lips, each of the annular lips configured to limit the gas fromescaping from the body between the nozzle and the annular seal.
 12. Thesealing device according to claim 7, further comprising: a guide inwhich the annular seal and the valve are disposed, the guide comprisingan opening configured to receive the nozzle therein.
 13. The sealingdevice according to claim 12, wherein the valve is disposed closer tothe opening than the annular seal.
 14. The sealing device according toclaim 7, wherein the valve is configured to vent the liquid or the gasfrom the body directly to atmosphere without equalizing pressure on bothsides of the valve.